These diamonds are nifty, I can’t believe I waited so long to revisit them! What I find fascinating about them is that as much asthe first digit in a row or column affects the cells separated by diamonds, cells separated by diamonds affect the first digit in the row or column. At least sometimes.
Another constraint I learned about from a Clover puzzle: imagine each diamond is a white Kropki dot, but instead of the difference between the two digits being one, it’s something else. In fact, if the diamond has digits to the left and right, then the number over in column one is the difference. But if the diamond has digits above and below, then the number up in row one is the difference. That’s X and Y part of XY-Difference Pairs.